Donald Trump's poll numbers took a nosedive in the first national survey after Iowa

Donald Trump. Joe Raedle/Getty Images Real-estate mogul Donald Trump's standing in the Republican presidential race deflated in the first national survey released after his loss to Sen. Ted Cruz of Texas in the Monday-night Iowa caucuses.

Trump remained in first place in the survey, which was conducted by the Democratic firm Public Policy Polling and was set to be released later Thursday. He received 25% of the vote from Republican-primary voters nationally. Cruz and Sen. Marco Rubio of Florida tied for second at 21% apiece.

Retired neurosurgeon Ben Carson grabbed 11%. None of the remaining Republican candidates received more than 5% of the vote.

It was a stark contrast from the national survey that Public Policy Polling released in mid-December. That poll found Trump, at 34%, maintaining a large national lead over both Cruz (18%) and Rubio (13%). Rubio seemed to benefit at Trump's expense with a stronger-than-expected showing in the Iowa caucuses, in which he nearly caught up to Trump. His poll standing was up 8 points from December.

As the candidates barrel toward New Hampshire, which on Tuesday will hold the election's first primary, early signs have shown Rubio to be climbing there after his Iowa performance.

The Public Policy Polling survey could also lend credence to many Rubio supporters' argument that he could be the Republican establishment's best option to take down Trump and Cruz, whose potential nominations have unnerved many in the party's mainstream.

The poll found the most support for Rubio in a theoretical three-man race for the nomination, with 34% picking the Florida senator compared with 33% for Trump and 25% for Cruz. He would also best Trump and Cruz in theoretical head-to-head bouts for the nomination. And his 64% favorability rating among Republican voters nationally trailed only Carson in that measure.